I don't know what happened to my FaceTime?

I have iPhone 4s. Last time I FaceTimed was… At least 4 weeks ago. The restriction is off, the camera is turned on, and FaceTime is on, too. However, there isn't an option/box/whatever-you-call-it for FaceTime on contacts… Oh, and I got my iPhone last November.

Try to backup your mobile. It may be some ios issue. By backing up your mobile it may fix the problem. Try it i'm not sure about that.